Construction of conventional structures, including both residential and commercial buildings, typically employ frame construction followed by exterior siding and interior finishing. For example, a home may be built by first constructing a wood frame with load-bearing walls and floor and ceiling joists extending between the walls. Commercial structures often employ steel rather than wood frames.
Once the framing is complete, exterior siding is then added to the frame. Walls may then be insulated with conventional insulating material, such as fiberglass insulation, to prevent thermal transfer between the exterior and interior of the building. Interior wall finish, such as Sheetrock, is then added. The ceilings and floors, between the floor and ceiling joists, are also frequently insulated.
This conventional technique has several drawbacks. For one, the method of construction is inefficient in that it requires a number of discrete steps to complete the installation of insulated walls. The siding step must be followed by a separate insulating step. Of course, this requires additional labor, and labor that is more expensive because it must be performed at the job site. The quality of the insulating job is also dependent upon the quality of the workmanship at the site, and may be adversely affected by exposure to weather-related elements. Furthermore, because much of the work in constructing insulated walls in the conventional manner must be done on-site, adverse weather can lead to significant delays in the construction process.
Additionally, the insulation is conventionally applied between the individual studs of the frame walls. Because there is no insulation applied to the exterior of the stud members, thermal bridging occurs across the stud members. In other words, heat from the interior of a structure can bridge across the stud members and escape into a colder exterior environment.
Various prefabricated wall panel systems have been devised which overcome many of the drawbacks of the conventional construction technique described above. For instance, the U.S. Pat. No. 4,628,650 issued to Parker and U.S. Pat. No. 5,349,796 issued to Meyerson disclose prefabricated building panels comprising an inner insulating core sandwiched between two outer layers. These panels improve upon on-site construction of building walls, but still suffer drawbacks eliminated by the present invention. For instance, the insulating core of these panels is left exposed along its perimeter. This allows for damage to the core during both the shipping and installation stages. An exposed core may also be susceptible to deterioration due to thermal drift. Certain insulating materials, such as urethane foam, suffer from the phenomenon known in the art as thermal drift, which is caused by the infusion of air through the foam cells and the resulting dilution of the insulating gas contained inside. Compounded with the intrusion of air into the cells is a flow of insulating gas out of the cells. Exposed insulating cores are also susceptible to deterioration due to weather related effects or insect infestation. The present invention eliminates these drawbacks by including a plastic channel that completely encapsulates and seals the insulating core.
Furthermore, the prior art panels are not assembled such that the insulating core is recessed both on one lateral side and one transverse end from the outer board surface, and equivalently protruded from the board layer on the opposite lateral side and transverse end of the panel. Without an offset of the insulating core both on the lateral sides and transverse ends, the user cannot ensure a tight seal between panels adjacent to one another or above one another in multiple story projects. The current invention is assembled with an offset insulating core that allows for the panels to be installed snugly against one another to reduce thermal bridging and air leaks between the interior and exterior of the building structure.